Improving Air Quality of Indoor Swimming Pools

Ir. J.G. Middendorf

20-03-2015

Indoor Pool Air Quality

Air quality of indoor swimming pools is

important for the health and comfort of staff

and guests

Recent Dutch regulations defines air quality

as a new control parameter

Conventional installation techniques are not

up to the task

“Best practice” solution

Indoor Pool Air Quality

1. Reduce the source of most air pollutants:

Good pool water treatment

2. Dilute the remaining volatile pollutants:

Adequate fresh air ventilation

Conventional installations

Two design goals:

1)Thermal comfort of staff and guests

PMV model of Prof. Fanger, ISO 7730, EN 15251

2) Protection of the building

No condensation, VDI 2089

Ventilation designs based on VDI 2089

Verein Deutscher Ingenieure

Technische Gebäudeausrüstung von

Schwimmbädern

Building Services in Swimming Pools

Technical guidelines

VDI 2089: evaporated water flow

Swimming hall air: T, pdl

Water: T, Ab, pdw

Evaporating water mass flow Mw

Fresh air mass flow Ma

Mw = ( b / ( Rd · Tm ) ) · (pdw – pdl) · Ab

VDI 2089: evaporated water flow

Mw = ( b / ( Rd · Tm ) ) · (pdw – pdl) · Ab

Mw : evaporating water flow, in kg/h

b : water transfer coefficient, in m/h, accuracy limitations

Rd : specific gas constant for water vapour, in J/kgK

Tm : arithmetic mean water and air temp., in K

pdw : saturation pressure water vapour at water temp., in Pa

pdl : water vapour pressure of the swimming hall air, in Pa

Ab : reference water area of the pool, in m2

VDI 2089: maximum fresh air flow

Ma = Mw / ( D x )

Ma : maximum fresh air flow, in kg/h

Mw : evaporating water flow, in kg/h

Dx : difference in humidity of the inside/outside air, in kg/kg

VDI 2089 section 6.2.1:

Dx = 5,3 g/kg, most humid summer month

Conventional installations

Fresh air component Theory & Practice

Outdoor Temperature Theory

VDI 2089

Conventional

Practice

Winter – 10°C 30% 20%

Mid-season 5°C 50% 40%

Summer >20°C 100% 100%

How to prevent

low Air Quality?

Modern Design: third design goal

1) Thermal comfort of staff and guests

2) Protection of the building

3) High air quality

Modern Design: high air quality

Solution:

High indoor air quality can be achieved by selecting heat recovery

systems with latent recovery during the winter and no latent

recovery during the summer

This is the case when the latent recovery is based on the principle

of condensation

Heat recovery + condensation

Special Rotary Heat Exchanger

Kantherm Heat Exchanger

Heat recovery + condensation

∆x Summer

∆x Winter

∆x Mid-season

Su

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ir

Exh

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air

Fresh air component Theory & Practice

Outdoor

Temperature

Theory

VDI 2089

Conventional

Practice

Modern Design

Practice

Winter – 10°C 30% 20% >50%

Mid-season 5°C 50% 40% >50%

Summer >20°C 100% 100% 100%

High Air Quality

Conclusion

A healthy and comfortable indoor climate can be achieved

in practice without any compromise by selecting heat

recovery systems with latent recovery during the winter and

no latent recovery during the summer.

The fresh air component will be up to three times as high.

This is a huge improvement of the pool air quality and a

good way to meet the new Dutch regulations.

Not according to Dutch regulations

Improving Air Quality of Indoor Swimming Pools

Ir. J.G. Middendorf

20-03-2015

Any Questions ?